I'm a fan of LESS. It's great. I'm a bigger fan of SASS (and I means .sass not .scss), but that's because of the syntax.

Whenever someone is evangelizing LESS they mention how it's better because it can be compiled on the browser via javascript. However they will also often mention that you wouldn't want to do this in production (I agree) which means setting up server side compilation (run time by the server) or design time compilation (thick client / command line).

So... what's the value in browser based javascript interpretation / compilation if you shouldn't be using it in production anyways?

I would even argue it's a negative in that it could encourage the bad practice of browser compilation.